Figure 7-17.--Typical displacement gyro and servo loops.
directional gyro (DG). These gyros mount in a
rotate 360° about the roll axis but follows the air-
common outer roll gimbal. The vertical gyro
craft in pitch and yaw.
provides pitch and roll signals and the directional
The vertical gyro pitch gimbal mounts in the
gyro provides heading (azimuth) signals. Erection
outer roll gimbal. This gimbal may rotate 360°
and leveling servo loops erect and maintain the
about the pitch axis but follows the outer roll
spin axis of the vertical gyro gravity vertical and
gimbal movements in roll and yaw. The gyro spin
the directional gyro spin axis parallel to the earth.
motor may rotate ±85° in roll but follows the
Roll, pitch, and azimuth control transmitters
vertical gyro pitch gimbal in pitch and yaw.
convert aircraft attitude and heading into electrical
Mechanical stops (not shown) limit inner roll
signals.
gimbal movement to prevent B101's spin axis,
aligning with the vertical gyro pitch gimbal axis.
VERTICAL GYROSCOPE OPERATION. --
Such an alignment would cause the vertical gyro
Look at figure 7-17 as you read this section. The
pitch gimbal to spin about its pitch axis (gimbal
vertical gyro consists of gyro spin motor B101
lock).
(which is the inner roll gimbal) and the vertical
gyro pitch gimbal. It also includes the outer roll
gimbal and the frame. The frame mounts to the
assembly case and follows all aircraft maneuvers.
brake (snubber) releases the outer roll gimbal from
The outer roll gimbal mounts in the frame. It may
the frame. The gyro spin motor starts, and
7-13